Silver-cleaning compound.



UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Dec. 18, 1906.

Application filed February 2,1906. Serial No. 299,068-

To all whom it may concern:

Be it known that I, WILLIAM H. RooMn, a citizen of the United States, and a resident of Derby, in the county of New Haven and State of Connecticut, have made and invented certain new and useful Improvements in Silver-Cleaning Compounds, of which the following is a specification.

My invention relates to a compound for cleansing and brightening silver or silver plated or covered articles, the object of the same being to improve upon the ordinary cyanid-of-potassium solution in several respects, and thereby effect a better cleansing action on the surface of the metal than has heretofore been possible.

IVith these and other ends in view the invention consists of a compound comprising the following ingredients and in substan tially the proportions named: soda-ash, six ounces; borax, one and one-half ounces; cyanid of potassium, one-half ounce. In practice these ingredients are first mechanically mixed in powdered form and when desired for use are dissolved in two quarts of water, preferably heated from 180 to 212 Fahrenheit.

The soda-as above mentioned is the article commercially made and sold under that name and containingfrom forty-eight to fiftyeight per cent. of sodium oxid. The action of this ingredient is to dissolve or release the bond that fixes the sulfid formed on the silver or silvered articles, which 'sulfid the cyanid of potassium in the solution will then remolve without affectingthe finish of the artic e.'

The borax combines with the other ingredients and assists in removing the tarnish from the metal and operates to whiten the same. I have found, however, that one-half to three-fourths ounce of ammonium chlorid may be substituted for an equivalent amount of borax, the chlorin in which assists in looswarm water, and dried, whereu on the appearance of the article will equa that when new. The comparatively small amount of cyanid of potassium present in the compound (the solvent action of which is somewhat modified by the soda-ash and borax) leaves the surface of the silver or silvered article in a particularly white, lustrous, and smooth condition, whereas in a compound consisting largely of cyanid of potassium the surface is left comparatively mottled, yellow, rough, and pitted. This is true of the action of the compound even on silver or silvered articles having thereon a satin finish, the latter being in no way marred by the action of the compound, whereas when subjected to ordinary cleansing solutions such finish is often parti ally or wholly destroyed.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A metal-cleaning compound consisting of soda-ash, six ounces; borax, one and onehalf ounces; and cyanid of potassium, onehalf ounce.

2. A compound containing soda-ash, bo-

rax, ammonium chlorid and cyanid of potassium, in substantially the proportions named. Signed at Derby, in the county of New Haven and State of Connecticut, this 31st day of January, A. D. 1906.

' WILLIAM H. ROOME. Witnesses:

CAROLINE S. HATHAWAY, HOWARD B. PEOK. 

